AUBURN, Alabama -- Patrick Miller's shot at a second chance started the moment Greg Robinson announced his intention to forego his final two seasons of eligibility and enter the NFL Draft.

Robinson's departure leaves a spot open on Auburn's formidable offensive line, a unit that returns four starters from one of the nation's best fronts.

Miller, who spent the final nine games of Auburn's magical run learning the consequences of an off-the-field mistake, is set on filling that hole.

Auburn right tackle Patrick Miller is refocused after an offseason mistake. (Julie Bennett/jbennett@al.com)

"The second half of the season's been a little rough for me, but honestly, just motivating for next year," Miller said. "In the offseason, I'm going to be more focused than anybody, because I've got something to fight for. I want to be back here, and I want to be in somewhat of a different position."

Miller has started 14 games in two seasons, holding down the right tackle spot for the final nine games of his freshman year in 2012 and the first five games of 2013.

Then Miller had to pay for a mistake he says he made during his freshman season, knocked out of the lineup for a three-game suspension.

"I was being immature, and I violated team rules," Miller said. "That's not going to happen again. I was a freshman when it all happened. It was between a coaching change, and it's probably the best thing that ever happened, because I learned a lesson. ... Follow the frickin' rules."

Except that Miller never earned his spot back. Finally healthy and recovered from a shoulder injury suffered as a freshman -- the shoulder injury that opened up a spot for Miller in the first place -- Avery Young grabbed hold of the right tackle spot and never let go, playing through a severe ankle injury during Miller's suspension and a broken hand suffered on the first play of the BCS National Championship.

During his three games away, Miller knew what was coming after he saw the film.

Young earned the right to start the final nine.

"He had the bump in the road," offensive line coach J.B. Grimes said. "It's an adverse situation for him, becausewe got on a roll as a football team, and you don't just start making wholesale changes when the chemistry is right."

Miller, at 6-foot-7, 290 pounds, and Young, a more powerful player at 6-6, 305 with a lot of athleticism, have been paired against each other since arriving on campus.

Off the field, Miller and Young get along well. A pair of Palm Beach natives, Miller, at Dwyer, said his high school is essentially right across the street from Palm Beach Gardens High, where Young played.

And they share some of the same interests. Both Florida boys love to fish.

But the relationship changes when the pair step on the practice field.

"On the field, it's all competition," Miller said. "I honestly believe that he's gotten me 10 times better than I would be. If he wasn't on this team, I wouldn't have that pressure of somebody on my heels, and the same way for him."

Miller's first order of business: Put on weight.

Built long and lanky, Miller's at around 290 pounds, short of the magical 300-pound mark that seems to be the benchmark for SEC tackles, a mark that Coleman and Young have already passed.

On an Auburn offensive line that still features three possible starters at tackle in sophomore Shon Coleman, Young and Miller, there is no room to take a false step in the pursuit of Robinson's left tackle spot.

Auburn right tackle Patrick Miller started the final nine games of the 2012 season as a true freshman. (Todd Van Emst/Auburn Media Relations)

"Shon Coleman, Patrick Miller, Robert Leff, we’re going to open that dude up and see who wins that job," Auburn coach Gus Malzahn said. "The good thing is we have a little bit of depth at that and have some experience."

Miller's adamant that he's changed off-the-field. From here on out, Miller says, he's focused on earning back a role among Auburn's starting five.

Few players understand the consequences of a mistake better.

"He's had to take a secondary role with our offensive line and with our football team, and it's not something he's used to," Grimes said. "It's a new day for him in the spring."